Apparatus for twisting and/or crimping yarn



A. DOBSON 2,939,269

APPARATUS FOR TWISTING AND/OR CRIMPING YARN June 7, 1960 Filed June 6,1958 INVENTOR AUS TIN DOBS ON A TORN APPARATUS FOR TWISTING AND/ ORCRIL'IPING- Austin Dobson, Macclesfield, England, assignor to ErnestScragg & Sons Limited, Macclesfield, England Filed June 6, 1958, Ser.No. 740,262 I Claims priority, application Great Britain June 11, 1957'3 Claims. c1. 57-774 The present invention concerns a device forimparting false twist to a textile yarn and, more especially, isconcerned with the production of crimped yarns from endless syntheticfilament yarns.

A false twist device which has been previously proposed includes twosets of rollers rotating in the same sense about parallel axespositioned so that the rollers of one set overlap the rollers of theother set to form cusps between adjacent overlapping rollers where theyarn passed generally parallel to the roller axes in'contact with theroller peripheries. Such a construction failed to provide a satisfactorytwisting action due to the difficulty of controlling the engagement ofyarn in the cusps.

An object of the present invention is to provide an improved false twistdevice which overcomes the foregoing disadvantages and which moreover isespecially suitable for incorporation in an apparatus for producingcrimped yarn by heating and imparting false twist to a synthetic endlessfilament yarn.

According to the present invention a device for imparting twist to atextile yarn traversing the said device comprises a pair of rotatedsurfaces so located relative to one another as to form a cusp in whichthe yarn to be twisted is held by a third rotating surface, the locationof the surfaces being such that the same degree and sense of twist isimparted to the yarn by all three surfaces.

Also according to the present invention a twisting device for textileyarns devised to apply a so-called false twist comprises two pairs ofrollers the rollers of each pair being located relative to the other soas to form similar cusps, and a third roller located between said pairs,the dimensions and location of the said rollers being such that a yarnrun between the cusps is deflected by the third roller from the straightline between the said cusps.

The invention will now be described further, by way of example withreference to the accompanying drawings, in which:

Fig. 1 is an end view of a preferred embodiment of false twisting unit;

Fig. 2 is a corresponding plan; and

Fig. 3 is a diagrammatic elevation of a crimping unit.

A false twisting arrangement for yarn comprises three rollers 11, 12 and13. All these rollers rotate in the same direction and the yarn passesinto the resultant twisting device via the cusp formed between therollers 11 and 12. All three rollers are contained within a supportingcase 14 and are driven from'a pulley 15 by means of a pulley 16. Thepulley 15 is carried on a short shaft passing through a bearing 17, theother end of the shaft being provided with a driving pulley 18 which isrotated by a belt 19. The latter belt may run the whole length of themachine and may serve a plurality of twisting heads of the type shown inthe figures.

The drive to the roller 11 is via a pulley 20 and the drive to theroller 13 is via a pulley 21. The pulley driving the roller 12 isimmediately beneath the pulley 20.

2 A yarn 22 passes through a guide eye 23 and thence, under slighttension, between rollers 11 and 12, both of which act to rotate the yarnabout its axis in the same direction,-while the yarn traverses in anupward diree:

tion with reference to Fig. 1. After leaving contact with,

the said rollers,'the yarn passes over the surface of roller 13, thissurface being displaced from the straightline of the yarn at its entryso that the yarn is held firmly against the gap'or cusp between therollers 11 and 12 and against the surface of the roller 13. The surfaceof the latter is preferably rounded as shown to prevent damage to theyarn. Similarly, the corners of the surfaces of rollers: 11 and 12 arealso slightly rounded, and if necessary one or more of the surfaces ofthe said rollers may be com-- posed of a resilient material such asrubber. Preferably, the surfaces of rollers 11 and 12 are of steel and acoating of resilient material having a high coefficient of friction, isapplied to the surface of roller 13.

After leaving the roller 13, the yarn may pass directly through the exiteye 24, but it has been found preferable in practice, to pass the yarnoncemore between two rollers 26 and 27 which rollers are of the sameshape and. size as the rollers 11 and 12, the roller 26 being locatedon,

the same shaft as roller 11 and roller 27 beinglocated on the same shaftas roller 12, so that the peripheral speeds, of the said pairs ofrollers, coincide. The rate of drive of all the rollers is such that theyarn receives an adequate degree of twist on one side of the twistinghead, thesaid twist being removed at the other side of the head.

In a crimping unit as shown in Fig. 3, the yarn 22 is drawn by adelivery roller Rfrom a yarn supply S through a tensioner T whereupon itis guided through or over a guide means, such as a guide eye G, as shownin the drawing, and is then drawn into contact with a heater H. Afterleaving the heater H, the yarn 22 passes through the guide eye 23 andthence into the false twisting device F.

It has been found that false twist arrangement enables a yarn such as,for example, one composed of monofilaments of nylon, to receive twist atan extremely high rate, preferably in excess of 50,000 r.p.m. whileinvolving relatively low rotational speeds of all the rollers associatedwith the said twisting operation. in fact, it is possible to obtain thesame degree of twist on the said yarn as is possible with presentmethods, with a considerably higher rate of transverse of the yarnthrough the apparatus. In addition, no high speed bearings are required,so that lubrication and driving problems are greatly simplified. Afurther advantage of the device is that since the rotational speeds ofall the moving parts with the exception of the yarn are low, very littlevibration and noise is occasioned.

The degree of divergence of the yarn from its original straight lineproduced by the roller 13 may, if required, be adjusted by altering theposition of the centre of retation of the shaft driving roller 13relative to the positions of the other two driving shafts supportingrollers 11 and 12. The amount of divergence must however be sufficientin conjunction with the yarn tension employed, to cause adequatetwisting effect to be imparted to the yarn.

The axial distance between adjacent faces of the rollers 11, 1'2 and 26,27 is preferably made small so that the yarn has no tendency to becometrapped between the said pairs of rollers. The distance between thefaces of rollers 12, 26 and 13 can also be made smaller, though this isnot thought to be essential.

It will be understood that the rollers may be mounted on shafts, or theymay be manufactured so that each shaft and its rollers are formed from asingle piece of material. Again, the rollers may be solid, with parallelPatented June 7, 1960 sides; or; they.- may be provided with webs whichare thinner than the surface flanges in order toiobtain light-4 ness. 7

I claim:

7 71-. A deviceiforimpartinglalsetwisttoajextile yarncomprising, incombination tworollers rotating-in the same. sense about parallet axespositioned 'so thatthe-two rollers overlap ,to form; a cuspvwhere the:yarn passes generally parajlelzto. theroller. ages in contact both 7roller peripheries, a thirdsrolleri also. rotating: inthe same.

sense about an axis parallel to the said: axis pressing'the yarn. intothe; said cusp, a. fourth roller-g rotating coaxially {with onehof thesaid first twoirollersandg a fifth-roller combination two; rollers.rotating in thesame sense about parallel axes positioned soathat the tworollers overlap rotating coarialty. with'the other of the said fiist tworollers, said; fourth and fifthrollers being; positioned so that-theyoverlap .to formra second cusp, said third roller deflecting theyarmfrqma. straight li-neibetween the cusp of: the-first; two.-roll'ers. and the cusp. of the fourthgandfifth; rollers V 2. A,twisting; device. for textile yarns devised to apply-- a sorcalledfalseiwist-comprising-rin combination two pairs of rollers, therollersofi each pair'being located relative to; thejother so; as to formsimilar-cusps, and a third roller located. between said; pairs ofrollers, the dimensions and locationsof the said-rollersbeing suchthat ayarn run between-the cusps is deflected-bythe third roller'from' thestraight line hetween the saidcusps.

' 3. false twist device for 'us e with a crimping 9 auna ase wh re ymfnassesee eratly parallel to the 'roller.axe-si i wllteel with bothrloller peripheries, a third roller also rotating in the same senseabout an axis parallel to the said' aie pressing-theyarn into the ids pit a r ha tel e ro ating qaxia ly wi h one. at

the said first't'wo rollers and a fifth roller rotating coaxially withthe otherofr-i the-sairl'= first two rollers, said fourth and fifthrollers being positioned so that they overlap to form a second cusp,said third roller deflecting the yarn from a straight line between thecusp of 'the' first two rollers and -the cusp of the: fourth and fifthrollers-i References Cited in the fileofthis: patent UNITEDSTATESTPATENTS 113,831 'A chibal'd' Apr. 1 8, 1 371 V 2,522,332, 7Abbott Sept- ,2, 1250 2,161 272, afidamme evalsem, 19 6.

